Effects of a blend of Saccharomyces cerevisiae-based direct-fed microbial and fermentation products on plasma carbonylmetabolome and fecal bacterial community of beef steers

Background:Previous studies have evaluated the metabolic status of animals fed direct-fed microbial(DFM)using enzyme-based assays which are time-consuming and limited to a few metabolites.In addition,little emphasis has been placed on investigating the effects of DFM on hindgut microbiota.We examined the effects of dietary supplementation of a blend of Saccharomyces cerevisiae-based DFM and fermentation products on the plasma concentrations of carbonyl-containing metabolites via a metabolomics approach,and fecal bacterial community,via 16S rRNA gene sequencing,of beef steers during a 42-day receiving period.Forty newly weaned steers were randomly assigned to receive a basal diet with no additive(CON;n=20)or a basal diet supplemented with 19 g of Commence™(PROB;n=20)for a 42-day period.Commence™(PMI,Arden Hills,MN)is a blend of 6.2×1011 cfu/g of S.cerevisiae,3.5×1010 cfu/g of a mixture of Enterococcus lactis,Bacillus subtilis,Enterococcus faecium,and Lactobacillus casei,and the fermentation products of these aforementioned microorganisms and those of Aspergillus oryzae and Aspergillus niger.On d 0 and 40,rectal fecal samples were collected randomly from 10 steers from each treatment group.On d 42,blood was collected for plasma preparation.Results:A total number of 812 plasma metabolites were detected.Up to 305 metabolites[fold change(FC)≥1.5,FDR≤0.01]including glucose,hippuric acid,and 5-hydroxykynurenamine were increased by PROB supplementation,whereas 199 metabolites(FC≤0.63,FDR≤0.01)including acetoacetate were reduced.Supplementation of PROB increased(P≤0.05)the relative abundance of Prevotellaceae UCG-003,Megasphaera,Dorea,Acetitomaculum,and Blautia.In contrast,the relative abundance of Elusimicrobium,Moheibacter,Stenotrophomonas,Comamonas,and uncultured bacterium belonging to family p-2534-18B5 gut group(phylum Bacteroidetes)were reduced(P≤0.05).Conclusions:The results of this study demonstrated that supplementation of PROB altered both the plasma carbonyl metabolome towards increased glucose concentration suggesting an improved energy status,and fecal bacterial community,suggesting an increased hindgut fermentation of the beef steers.

Morphological and microsatellite DNA diversity of Nigerian indigenous sheep

Background： Sheep is important in the socio-economic lives of people around the world. It is estimated that more than half of our once common livestock breeds are now endangered. Since genetic characterization of Nigerian sheep is still lacking, we analyzed ten morphological traits on 402 animals and 15 microsatellite DNA markers in 384 animals of the 4 Nigerian sheep breeds to better understand genetic diversity for breeding management and germplasm conservation. Results： Morphological traits of Uda and Balami were significantly （P 〈 0.05） higher than Yankasa, which were both higher than West African Dwarf （WAD） sheep. Stepwise discriminant analysis showed tail length, rump height, chest girth, ear length and chest depth as the most discriminating variables for classification. Mahalanobis distances show the least differentiation between Uda and Balami and the largest between WAD and Balami sheep. While 93.3% of WAD sheep were correctly assigned to their source genetic group, 63.9% of Yankasa, 61.2% of Balami and 45.2% of Uda were classified correctly by nearest neighbour discriminant analysis. The overall high Polymorphism Information Content （PIC） of all microsatellite markers ranged from 0.751 to 0.927 supporting their use in genetic characterization. Expected heterozygosity was high for all loci （0.783 to 0.93）. Mean heterozygote deficiency across all populations （0.17] to 0.534） possibly indicate significant inbreeding （P 〈 0.05）. Mean values for FST, FIT and F^s statistics across all loci were 0.088, 0.394 and 0.336 respectively. Yankasa and Balami are the most closely related breeds （DA = 0.184） while WAD and Balami are the farthest apart breeds （DA-- 0.665）, which is coincident with distance based on morphological analysis and population structure assessed by STRUCTURE. Conclusions： These results suggest that within-breed genetic variation in Nigerian sheep is higher than between-breeds and may be a valuable tool for genetic improvement and conservation. The higher genetic variability in Yankasa suggests the presence of unique ancestral alleles reflecting the presence of certain functional genes which may result in better adaptability in characteristics are potentially useful in planning indigenous sheep. more agro-ecological zones of Nigeria. These genetic mprovement and conservation strategies in Nigerian

Molecular Diagnosis of Subclinical African Trypanosoma vivax Infection and Association with Physiological Indices and Serum Metabolites in Extensively Managed Goats in the Tropics

Trypanosomosis remains a major challenge to livestock production in much of tropical Sub-Saharan Africa, while diagnosis and treatment still depend on inefficient parasitological techniques. Endemic infections depend on animal reservoirs with subclinical parasitemia. We report molecular diagnosis of subclinical Trypanosoma vivax (T. vivax) infection using polymerase chain reaction (PCR) for the first time in Nigerian goats and associate parasite presence with gross physiological traits and serum metabolites in extensively managed Nigerian goats. PCR was used to amplify a 400 bp DNA fragment of the parasite genome in 205 goats across three geographical zones of the country. Results showed a high subclinical infection rate (SCIR) of 71.7% in the total goats examined. Overall SCIRs of 71%, 75.9% and 55.6% were recorded in West African Dwarf, Red Sokoto and Sahel goats respectively, while geographical SCIRs were 71.2% (Southwest), 75% (Northwest) and 70% (Northeast). T. vivax presence had significant (P 0.05) effect on respiratory rate and is associated with higher creatinine levels in sera. Logistic regression analyses with Hosmer-Lemeshow goodness-of-fit showed that respiratory rate is the most important predictive trait for the presence of T. vivax infection (P 0.05). Goats appear to be a viable reservoir for T. vivax infection of other livestock. Molecular diagnosis of subclinical trypanosomosis using PCR could be useful for large scale epidemiological studies, early diagnosis of subclinical infection and treatment of the disease in extensively managed tropical goats.

Novel intron 2 polymorphism in the melanophilin gene is in Hardy-Weinberg equilibrium and is not associated with coat color in goats

Pigmentation plays important adaptation and physiological efficiency roles in animals. In the sequence of a 648 bp fragment representing intron 1, exon 2, and part of intron 2 of the MLPH mammalian pigmentation gene, we identified a novel g.469C> G mutation in intron 2, and genotyped it in 266 Nigerian goats using PCR-RFLP analysis. The C allele had frequencies of 0.9625, 0.9804 and 0.97405 in West African Dwarf (WAD),Sahel(SH) and Red Sokoto (RS) breeds, respectively. The G allele was the highest in WAD (0.0375), followed by RS (0.02595), and then SH (0.0196). Overall low FIS and FST and high Nm values demonstrate little differentiation within and among the goat breeds at this intronic locus. This g.469C> G polymorphism in MLPH gene is the first in any goat breed and also first in Nigerian goats. Our results suggest that this intronic SNP locus is maintained at Hardy-Weinberg equilibrium (P < 0.05) and the lack of association of this SNP with coat color may indicate its neutrality in goats.

Nanotechnology in aquaculture: Applications, perspectives and regulatory challenges

Aquaculture is considered one of the most important food production systems both in terms of economic impact and food security,and the ongoing development of this industry is a key factor in the strategy to guarantee global nutritional safety.Nowadays,different types of nanotechnology-based systems have been employed to increase its production,efficiency and sustainability.Recent efforts have been made in the fields of health management,enhancement of fish and shellfish development by dietary supplementation with nutraceuticals,but also in the processing and preservation of seafood and water treatment,among others.Therefore,nanotechnology has a significant role to play in the improvement of the efficiency and the environmental impact of this industry.Given this perspective,we propose to review the current situation of nanotechnology in the field of aquaculture and fisheries,emphasizing not only in current applications,and future prospects,but also in the ethical and governance aspects associated with this topic.